The present invention relates to a rim for the mounting and travel of a tubeless tire, that is to say a tire without inner tube, intended to equip vehicles of "heavy truck" types, such as trucks, buses, and "subway trains". It also relates to a rolling assembly formed of such a rim and a tubeless tire having beads of a special structure.
If we consider the rims of the rolling assemblies presently used, we can distinguish primarily so-called hollow base rims which have frustoconical seats inclined by an angle of 5.degree. or 15.degree. to the axis of rotation of the assembly, and rims with a flat or practically flat base having seats inclined either 0.degree. or 5.degree. with respect to the axis of rotation.
The so-called hollow-base rims have a mounting groove the diameter of which is definitely less than the nominal diameter of the rim. This inside diameter of the rim is considered by the users to be too small and does not make it possible to select brake drums of dimensions suitable for effective braking of the vehicles, which are becoming more and more powerful.
It is extremely desirable to increase the diameter of the rim base, and to do so to the greatest extent possible, without increasing the overall diameter of the rolling assembly, which comes down to using a rim with a flat base, the diameter of the base being substantially equal to the nominal diameter of the rim.
For the mounting of tubeless tires, a flat-base rim requires the presence of at least one removable side ring, a locking ring, and a sealing joint and further requires that the rim base be provided with a fixed flange on the side opposite the side where the parts are removable. At least three parts are therefore necessary. In most cases, the number of parts necessary is greater than three and may at times reach six in the case of the 37 heavy truck" rims of large dimensions; except for the sealing joints, the parts of a rim are made of metal and are therefore bulky and heavy. Furthermore, these metal parts are frequently subject to partial, localized wear with or without oxidation and formation of rust which damage, upon subsequent use, leads to defective mountings with loss of pressure and also the creation of a concentration of stresses which may result in the breaking of parts and accidents. Furthermore, vulcanized rubber sealing joints, as is known, require a great deal of care with regard to their placing; furthermore, they are subject to natural oxidation and hence to cracks. Thus, in many cases the conditions are such that these joints do not satisfactorily play the role for which they were intended.